#include <iostream>
#include <random>
#include <windows.h>
#include <ctime>
#include <conio.h>

using namespace std;

bool gameOver;
const int width = 20;
const int height = 20;
int x, y, fruitX, fruitY, score;
int tailX[100], tailY[100];
int nTail;

default_random_engine generator(time(NULL));
uniform_int_distribution<int> rangeW(0, (width-1)), rangeH(0, (height-1));

enum eDirection { STOP = 0, LEFT, RIGHT, UP, DOWN};
eDirection dir;

void setup() {
	gameOver = false;
	dir = STOP;

	x = width / 2;
	y = height / 2;

	fruitX = rangeW(generator);
	fruitY = rangeH(generator);

	score = 0;
}

void draw() {
	system("cls");

	cout << "Score: " << score << endl;

	for (int i = 0; i < width+2; i++) {
		cout << '#';
	}
	cout << endl;

	for (int i = 0; i < height; i++) {

		for (int j = 0; j < width; j++) {
			if (j == 0) {
				cout << '#';
			}

			if (i == y && j == x) {
				cout << 'O';
			}
			else if (i == fruitY && j == fruitX) {
				cout << '@';
			}
			else {
				bool print = false;
				for (int k = 0; k < nTail; k++) {

					if (tailX[k] == j && tailY[k] == i) {
						cout << '*';
						print = true;
					}
				}
				if (!print) {
					cout << ' ';
				}
			}

			if (j == (width-1)) {
				cout << '#';
			}
		}
		cout << endl;

	}

	for (int i = 0; i < width+2; i++) {
		cout << '#';
	}
	cout << endl;

}

void input() {
	if (_kbhit()) {
		switch (_getch()) {
		case 'w':
			dir = UP;
			break;
		case 'a':
			dir = LEFT;
			break;
		case'd':
			dir = RIGHT;
			break;
		case 's':
			dir = DOWN;
			break;
		case 'p':
			gameOver = true;
			break;
		}
	}
}

void logic() {
	int prevX = tailX[0];
	int prevY = tailY[0];
	int prev2X, prev2Y;
	tailX[0] = x;
	tailY[0] = y;

	for (int i = 1; i < nTail; i++) {
		prev2X = tailX[i];
		prev2Y = tailY[i];
		tailX[i] = prevX;
		tailY[i] = prevY;
		prevX = prev2X;
		prevY = prev2Y;

	}

	switch (dir)
	{
	case LEFT:
		x--;
		break;
	case RIGHT:
		x++;
		break;
	case UP:
		y--;
		break;
	case DOWN:
		y++;
		break;
	default:
		break;
	}

	if (x > width || x < 0 || y > height || y < 0) {
		gameOver = true;
	}
	for (int i = 0; i < nTail; i++) {
		if (tailX[i] == x && tailY[i] == y) {
			gameOver = true;
		}
	}

	if (x == fruitX && y == fruitY) {
		score++;
		nTail++;

		fruitX = rangeH(generator);
		fruitY = rangeW(generator);
	}

}

int main() {

	setup();
	while (!gameOver) {
		draw();
		input();
		logic();
		Sleep(10);
	}
}